CVE-2026-33811
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Go standard library | net | 0 < 1.25.10 | affected |
| Go standard library | net | 1.26.0-0 < 1.26.3 | affected |
Weaknesses
- CWE-415: Double Free
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: yes
- Technical Impact: partial
net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME
Additional References
- https://access.redhat.com/security/cve/CVE-2026-33811
- https://bugzilla.redhat.com/show_bug.cgi?id=2467822
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33811.json
- https://access.redhat.com/errata/RHSA-2026:34357
- https://access.redhat.com/errata/RHSA-2026:34359
- https://access.redhat.com/errata/RHSA-2026:34364
- https://access.redhat.com/errata/RHSA-2026:33574
- https://access.redhat.com/errata/RHSA-2026:23262
- https://access.redhat.com/errata/RHSA-2026:23264
- https://access.redhat.com/errata/RHSA-2026:33120
- https://access.redhat.com/errata/RHSA-2026:33123
- https://access.redhat.com/errata/RHSA-2026:33142
- https://access.redhat.com/errata/RHSA-2026:33150
References
- https://go.dev/issue/78803
- https://go.dev/cl/767860
- https://groups.google.com/g/golang-announce/c/qcCIEXso47M
- https://pkg.go.dev/vuln/GO-2026-4981
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